code: def get_backgrounds(cache_dir=None):
      """Download a set of pre-reviewed backgrounds.
  
      Args:
          cache_dir: Where to save the dataset. By default, data will be
              saved to ~/.keras-ocr.
  
      Returns:
          A list of background filepaths.
      """
      if cache_dir is None:
          cache_dir = os.path.expanduser(
              os.path.join("~", ".keras-ocr")
          )
      backgrounds_dir = os.path.join(cache_dir, "backgrounds")
      backgrounds_zip_path = tools.download_and_verify(
          url="https://github.com/faustomorales/keras-ocr/releases/download/v0.8.4/backgrounds.zip",
          sha256="f263ed0d55de303185cc0f93e9fcb0b13104d68ed71af7aaaa8e8c91389db471",
          filename="backgrounds.zip",
          cache_dir=cache_dir,
      )
      if len(glob.glob(os.path.join(backgrounds_dir, "*"))) != 1035:
          with zipfile.ZipFile(backgrounds_zip_path) as zfile:
              zfile.extractall(backgrounds_dir)
      return glob.glob(os.path.join(backgrounds_dir, "*.jpg"))
  
imports: import os
  import math
  import glob
  import typing
  import random
  import zipfile
  import string
  import itertools
  import cv2
  import tqdm
  import numpy
  import essential_generators
  import PIL.Image
  import PIL.ImageDraw
  import PIL.ImageFont
  import fontTools.ttLib
  from .None import tools
label_desc: Use image node_id 7 for calling a global function with example usage: get_backgrounds(cache_dir) and returns: glob